Production of blown asphalt



July 5, 1938. J. s. WALLIS ET AL PRODUCTION OF BLOWN ASPHALT Filed Jan.31, 1950 INVENTORS J \444; i

aka; 4,} 1 #vrATToRNEY than 20 Baum.

Patented July 5, 1938 PATENT OFFICE PRODUCTION OF BLOWN ASPHALT JohnSamuel Wallis, New York, and Harry R. Swanson, White Plains, N. Y.,assignors to Foster Wheeler Corporation, New York, N. Y., a corporationof New York Application January 31, 1930, Serial No. 424,918

8 Claims. (01. 196-74) Our invention relates to treatment of hydrocarbonfor the production of asphalt.

The practice in the past in treating heavy hyrdrocarbons for theproduction of asphalt has been to treat hydrocarbons in a suitableprocess as a result of which a component derived will be suitable forfurther treatment to produce asphalt. This asphalt component, or wemight say, the residual flux oil from crude distillation, is thenconducted to a horizontal cylindrical member which we may term a still,but which is hollow inside and without any internal constructions forflow of liquids so that the liquid all exists in one body as a largepool in such horizontal still. This liquid is then treated by blowinginto it an oxidizing material such as air or superheated steam, andafter this process has gone on for a while, the supply of air orsuperheated steam is shut off and the batch is withdrawn and anotherbatch introduced. We may term this a batch process.

Indistinction to the batch process, we propose a continuous process forthe production of blown asphalt, and to that end we propose to utilize adifferent type of structure in which a different process takes place.The structure may be of various forms and may be described by sayingthat it is similar to a fractionating tower. The purpose of using atower similar to a fractionating tower is to obtain continuous flow ofthe hydrocarbon liquid downwardly overv a series of trays and to havecontinuous upflow of the oxidizing gas in contact intermittently withliquid bodies of the hydrocarbon.

As a further feature of our novel process, we utilize the heat developeddue to the exothermic character of the reaction to carry on the process.The hydrocarbon used for this purpose is a hydrocarbon of high secifivgravity, for example, greater The supply of oxidizing fluid is regulatedin such a manner as to give a temperature such that the process takesplace below the vaporizing point of the hydrocarbon, but above the pointwher reaction begins to take place so that the p cess is one of reactionas distinguished from the mere formation of a physical mixture as byabsorption.

The invention will become apparent and the nature and advantages thereofwill be readily understood by reference to the following specificationwhich describes the process, in conjunction with the diagrammaticshowing of an apparatus on the accompanying drawing, it being drawing isfor illustrated purposes only in an aid to understanding the invention.

Referring to the drawing:

Reference character designates a heater comprising tubes ll throughwhich the hydrocarbon may be passed for the purpose of its .beingheated. This is on the assumption that the process begins with a coldhydrocarbon. The hydrocarbon is passed through the pipe [2 and pipe l3and enters the tower 14. Tower II contains a series of bubble trays l5which may be of any various known constructions. The oil is shown asintroduced on the top tray, but may be introduced at various points inthe tower. The oil cascades downwardly from tray to tray in the tower inknown manner.

Reference character i6 designates a separately fired heater containingtubes il in which the oxidizing fluid is heated. The oxidizing fluid maybe air or steam. The oxidizing fluid enters through the pipe l8, passesthrough the separately fired heater and through pipe l9 into the lowerpart of the tower, where it may be introduced through a perforated pipearrangement 20.

The oxidizing gas passes upwardly through the tower and successivelythrough the ports of the bubble, trays, thus flowing in intimate contactwith the continuously downwardly cascading hydrocarbon.

If the temperature is too low in the tower, reaction will not takeplace. Our process contemplates the existence in the tower of so high atemperature that reaction takes place and the oxygen chemically uniteswith the hydrocarbon as distinguished from mere absorption. Furthermore,the temperature must not be so high that the hydrocarbon vaporizes toany material extent since the purpose of the process is to maintain thehydrocarbon of suitable constituency to produce desired quality ofasphalt. Consequently, we maintain the temperature between the limitsindicated, which may be, for example, between 300 degrees Fahrenheitand700 degrees Fahrenheit, depending upon the nature of the hydrocarbonused.

Gases, principally non-condensible gases derived from the oxidizingmedium, are removed from the top of the tower through pipe 2| and passto a cooler 9 in which any condensible gases may be liquefied.

The finished product is withdrawn from the bottom of the tower throughthe pipe 23 and passes through a heat exchanger 24 and to a point ofstorage. The incoming hydrocarbon may be pumped by a pump 25 through theheat exchanger 24 and thence to the tubes ll of the heater.

great extent upon the nature of the fluids used. To illustrate, in eventthat the hydrocarbon is received from the previous distillation process,it may be necessary to cool the hydrocarbon rather than to heat it, andin such case the heater l0 may be replaced by a cooler. Also, thetemperature of the oxidizing gas is important, and

in order to obtain a regulation of this factor we provide a by-pass pipe22 around the heater I6.

The nature of our process, within the limits of temperature indicated,is such that the reaction is exothermic, and we utilize the heatinternally developed to maintain the temperature. Assuming that the oilhas first been heated in a heater Ill, the temperature will rise in thetower to the point where it is necessary to diminish the heating. Also,we provide a by-pass 21 around the heater and the process may go on insuch manner that no heat is supplied, the exothermic heat supplying allthe heat that is necessary. Suitable valves are obviously provided totake care of the flow through the various pipes so that when, forexample, the by-pass 21 is being used, flow is cut off through theheater Ill. Obviously, the flow may be proportioned as between theby-pass pipe and the heater I0.

We may further control the process by inserting a temperature-regulatingcoil at one or more points in the tower as indicated at 28. We maycontrol the flow of a cooling fluid or a heating fluid through suchcooling coil in order to maintain the temperature within desired limits.Obviously, it is possible toautomatically control the flow of coolingfluid, such as water, through the cooling coil 28 in response totemperature at one or a number of points in the tower so as to maintaina desired temperature automatically. To illustrate this, we haveindicated diagrammatically a temperature-responsive element 29 withinthe tower as controlling a valve 30 regulating the flow offluid throughthe coil 28.

Obviously, the quality of the product obtained can be governed by therelative proportions of hydrocarbon and oxidizing fluid supplied to thetower. Furthermore, this may be regulated by adjusting the flow on thetrays. For a higher degree of oxidation, either the time of flow of thehydrocarbon through the tower may be extended over a greater period oftime or the amount of oxidizing fluid may be increased to give thedesired product.

We prefer to carry out our process at substantially atmospheric pressureand regulate the product by control of the temperature. It is obviouslypossible, however, to-vary the pressure within the tower, and variationsof pressure will effect temperature values in manner depending uponknown laws of fluids.

It will be seen from the above that we may term the inside of the towera reaction zone.

What we claim is:

1. The process of oxidizing an asphalt component of a hydrocarbon fluidfor the production of blown asphalt which consists in continuouslycascading the asphalt component downwardly through a reaction zone,continuously passing an oxidizing gas upwardly through the reaction zonein intermittent and direct contact with the downwardly cascading asphaltcomponent to thereby oxidize the asphalt component and regulating thetemperature at an intermediate point in the reaction zone to maintainthetemperature within limits below temperature of substantialvaporization of the asphalt component and suificiently It will be seenthat the process depends to a I high to eiiect chemical reaction betweenthe asphalt component and the oxidizing gas.

2. The process of oxidizing an asphalt compooxidize the asphaltcomponent and automatically regulating the temperature at anintermediate point in the reaction zone to maintain the temperaturewithin limits below temperature of substantial vaporization of theasphalt component and sufficiently high to eifect chemical reactionbetween the asphalt component and the oxidizing gas.

3. The process of oxidizing an asphalt component of a hydrocarbon fluidfor the production of blown asphalt which consists in continuouslycascading the asphalt component downwardly through a reaction zone,continuously passing an oxidizing gas upwardly through the reaction zonein intermittent and direct contact with the downwardly cascading asphaltcomponent to thereby oxidize the asphalt component, utilizing the heatproduced in the reaction zone as a result of the oxidation for carryingon the process and regulating the temperature at an intermediate pointin the reaction zone to maintain the temperature within limits belowtemperature of substantial vaporization of the asphalt component andsumciently high to eifect chemical reaction between the asphaltcomponent and the oxidizing gas.

4. The process of oxidizing an asphalt component of a hydrocarbon fluidfor the production of blown asphalt which consists in continuouslycascading the asphalt component downwardly through a reaction zone,continuously passing an oxidizing gas upwardly through the reaction zonein intermittent and direct contact with the downwardly cascading asphaltcomponent to thereby oxidize the asphalt component, utilizing the heatproduced in the reaction zone as a result of the oxidation for carryingon the process and automatically regulating the temperature at anintermediate point in the reaction zone to maintain the temperaturewithin limits below the temperature of substantial vaporization of theasphalt component arid sufliciently high to eflect chemical reactionbetween the asphalt component and the oxidizing gas.

5. The process of oxidizing an asphalt component of a hydrocarbon fluidfor the production of blown asphalt which consists in continuouslycascading the asphalt component downwardly over bubble trays in a tower,continuously passing an oxidizing gas upwardly through said towerindirect contact with the downwardly cascading asphalt component tothereby oxidize the asphalt component and regulating the temperature atan intermediate point in the tower between bubble trays to maintain thetemperature within limits below temperature of substantial vaporizationof the asphalt component and sufliciently high to effect chemicalreaction between the asphalt component and the oxidizing gas.

6. The process of oxidizing an asphalt component of a hydrocarbon fluidfor the production of blown asphalt which consists in continuouslycascading the asphalt component downwardly over bubble trays in a tower,continuously passing an oxidizing gas upwardly through said tower indirect contact with the downwardly cascading asphalt component tothereby oxidize the asphalt component, utilizing the heat produced inthe tower as a result of the oxidation for carrying on the process andregulating thetemperature at an intermediate point in the tower betweenbubble traysto maintain the temperature within limits below temperatureof substantial vaporization of the asphalt component and suilicientlyhigh to effect chemical reaction between the asphalt component and theoxidizing gas.

7. Apparatus for treating an asphalt component of a hydrocarbon fluid toproduce blown asphalt comprising a tower, bubble trays in said tower,means for supplying asphalt component to 'said tower to cascadedownwardly over the bubble trays, means for regulating the tempera tureof the asphalt component comprising a first heater and a by-pass aroundsaid heater, means for supplying a gaseous oxidizing agent to said towerto flow upwardly in direct contact with the downwardlycascading asphaltcomponent, means for regulating the temperature of the gaseous oxidizingagent comprising a second heater and a by-pass around said secondheater, a conduit in said t wer between bubble trays.

conduit and means responsive to temperature between bubble trays in saidtower for regulating flow or cooling medium through said conduit.

8. Apparatus for treating an asphalt component of a hydrocarbon fluid toproduce blown asphalt comprising a tower, bubble trays in said tower,means for supplying asphalt component to said tower to cascadedownwardly over the bubble trays, means for regulating the temperatureof the asphalt component comprising a first heater and a by-pass aroundsaid heater, means for supplying a gaseous oxidizing agent to said towerto flow upwardly in direct contact with the downwardly cascading asphaltcomponent, means for regulating the temperature of the gaseous oxidizingagent comprising a second heater and a by-pass around said secondheater, cooling means in the intermediate portion of said tower andmeans responsive to temperature in the intermediate portion 01 saidtower for controlling said cooling means.

0 JOHN SAIMUEL WALLIS. HARRY R. SWANSON.

, means for supplying a cooling medium to said

